We tested two versions: the Turbo and the 4S. The Turbo has a more powerful V8 engine. According to Porsche, the 4S can go from 0-60 mph in 4 seconds. Top speed: 179 mph. Its V6 engine has 440-horsepower. The Panamera starts at $85,000. It can be as much as $150,000 with added options.